The present invention relates generally to rendition style determination apparatus, methods and programs for determining a musical expression to be imparted on the basis of characteristics of performance data. More particularly, the present invention relates to an improved rendition style determination apparatus and method which determine a rendition style to be imparted, in accordance with propriety (or appropriateness) of application (i.e., applicability) of the rendition style, to two partially overlapping notes to be sounded in succession. Further, the present invention relates to an improved rendition style determination apparatus and method which, in accordance with predetermined pitch range limitations, determine applicability of a rendition style designated as an object to be imparted and then determine a rendition style to be imparted in accordance with the thus-determined applicability.
In recent years, electronic musical instruments have been popularly used which electronically generate tones on the basis of performance data generated in response to operation, by a human player, of a performance operator unit or performance data prepared in advance. The performance data for use in such electronic musical instruments are constructed as, for example, MIDI data corresponding to notes and musical signs on a musical score. However, if respective tone pitches of a series of notes are represented by only tone pitch information, such as note-on information and note-off information, then an automatic performance of tones executed, for example, by reproducing such performance data tends to become mechanical and expressionless and hence musically unnatural. Thus, there have heretofore been known apparatus which are designed to make a performance-data-based performance more musically natural, beautiful and vivid, such as: apparatus that can execute a performance while imparting the performance with rendition styles designated in accordance with user's operation; and apparatus that determines various musical expressions, representing rendition styles etc., on the basis of characteristics of performance data so that it can execute a performance while automatically imparting the performance with rendition styles corresponding to the determination results. Among such known apparatus is the apparatus disclosed in Japanese Patent Application Laid-open Publication No. 2003-271139 (corresponding to U.S. Pat. No. 6,911,591). In the conventionally-known apparatus, determinations are made, on the basis of characteristics of performance data, about various musical expressions and rendition styles (or articulation) characterized by a musical instrument and the rendition styles are imparted to the performance data. For example, each position, suitable for execution of a staccato, legato or other rendition style, is automatically searched or found from among the performance data, and then performance information (e.g., rendition style designating event), capable of achieving a rendition, such as a staccato or legato (also called “slur”), is newly imparted to the thus-found position of the performance data.
In order to allow an electronic musical instrument to reproduce more realistically a performance of a natural musical instrument, such as an acoustic musical instrument, it is essential to appropriately use a variety of rendition styles; any rendition styles are, in theory, realizable by a tone generator provided in the electronic musical instrument. However, if a performance on an actual natural musical instrument is considered, it is, in practice, sometime difficult for the actual natural musical instrument to execute the performance and impart some designated rendition styles due to various limitations, such as those in the construction of the musical instrument, characteristics of the rendition styles and fingering during the performance. For example, despite the fact that it is very difficult for an actual natural musical instrument to impart a glissando rendition style to two partially overlapping notes to be sounded in succession because a tone pitch difference (i.e., interval) between the two notes is extremely small, it has been conventional for the known apparatus to apply as-is a glissando rendition style having been determined (or designated in advance) as a rendition style to be imparted to such two partially overlapping notes. Namely, in the past, even where a rendition style designated as an object to be imparted is an unsuitable one that is difficult to execute even on a natural musical instrument, the designated rendition style would be undesirably applied as-is, which thus results in a performance with a musically unnatural expression.
Further, in not only actual natural musical instruments but also electronic musical instruments of different model types and/or makers etc., there are some limitations in the pitch range specific to the musical instrument or in a user-set available pitch range (in this specification, these pitch ranges are referred to as “practical pitch ranges”). Thus, when a performance is to be executed on an electronic musical instrument using a desired tone color of a natural musical instrument, impartment of some rendition style, designated as an object to be imparted, is sometimes inappropriate. Regarding impartment of a bend-up rendition style, for example, it is not possible to use an actual natural musical instrument to execute a performance while effecting a bend-up from outside the practical pitch range into the practical pitch range. However, the conventional electronic musical instruments are constructed to apply as-is a bend-up rendition style, determined (or designated in advance) as an object to be imparted, and thus, even a bend-up from outside the practical pitch range into the practical pitch range, which has heretofore been non-executable by actual natural musical instruments, would be carried out in the electronic musical instrument in undesirable form; namely, in such a case, the performance by the electronic musical instrument tends to break off abruptly at a time point when the tone pitch has shifted from outside the practical pitch range into the practical pitch range in accordance with the bend-up instruction. Namely, even where a rendition style to be imparted is of a type that uses a pitch outside the practical pitch range and hence is non-realizable with a natural musical instrument, the conventional technique applies such a designated rendition style as-is, which would result in a musically unnatural performance.